(1) Field of the Invention
This invention relates generally to a battery assembly, and more particularly to an assembly technique to incorporate electronic functions within removable battery packs, where all components are interconnected using a lead frame technology.
(2) Description of Prior Art
Many portable electronic devices require removable battery packs. Sometimes electronic monitoring and control functions communicating between the battery and said electronic device are incorporated within the battery pack. Usually the bare battery cells have to be mounted together with any required electronics into a sealed housing with exposed electrical contacts to connect the pack to the electronic device using it.
Normally, semiconductor chips are mechanically connected to a chip-carrier, typically a lead frame in today's technology, which is then connected to a printed circuit board. Further connecting devices would then connect to said printed circuit board. A plastic case with a bottom and top element would then enclose the whole assembly
Integrated semiconductor modules often use the lead frame technology to carry the semiconductor chip and to connect the chip pads with a larger printed circuit board. These lead frames are normally encapsulated with a convenient plastic material. FIG. 1 (prior art) shows the cross sections of two typical examples of said semiconductor modules. FIG. 2 shows a bare lead frame, which is produced as a long tape of metal sheet. The basic material of lead frames is sheet metal. The leads are either metal-stamped or etched to form the leads, therefore complex forms of said leads can be achieved. The leads are typically pre-formed in a bending process to accommodate all kinds of shapes. A frame area around all leads holds said leads in position, until the chips are mounted and the assembly has been encapsulated (molded) into plastic material.
U.S. Patent (U.S. Pat. No. 5,498,903 to Dioxin et al.) describes an integrated circuit package of the surface-mountable type within which a battery is mounted. Battery leads extend from the side of the package body opposite that which is adjacent the circuit board when mounted, and between which a conventional battery may be placed. A gap is present between the housing and the battery. The gaps thermally insulate the battery from the package body and housing, so that the circuit may be subjected to solder reflow mounting to a circuit board, while insulating the high temperature from the battery.
U.S. Patent (U.S. Pat. No. 6,109,530 to Larson et al.) discloses a chip-battery micro-module and fabrication there of wherein an integrated circuit “chip” is secured to a battery coin cell using various conductive and insulating layers that provide power to the chip. The chip-battery micro-module may be used to power an electronic accessory that is directly attached thereto, such as an LCD display or speaker, or to power a circuit in a smart card or electronic device such as a portable phone. The chip battery micro-module can be integrated into a plastic smart card.
U.S. Patent (U.S. Pat. No. 6,284,406 B1 to Xing et al) shows an IC card comprising an electronic device and a battery within a plastic card for electrically energizing the electronic device. The battery is comprised as a monolithic electrochemical cell having a lithium-containing cathode, a carbon anode, and a porous polymer separator infused with electrolyte solution. The cell has a thickness of less than 0.7 mm. The battery has an overall thickness of less than 0.8 mm.